The present invention relates to a detent mechanism of the type having a plurality of detent plungers arranged in circumferentially spaced apart relation for detent engagement with a valve spool.
Many hydraulic control valves employ detent mechanisms of the type generally contemplated by the present invention for maintaining the spool of the control valve in a preselected position. It is also common to employ a kickout device for releasing the detent mechanism and allowing the spool to be repositioned or to return to a neutral position.
Within such detent mechanisms, detent elements such as plungers or ball bearings are spring-loaded for resilient engagement with angular grooves or ridges in the control spool and thus tend to maintain the spool in one or more preselected positions. In many such valves, two or more detent elements are arranged in opposition to each other for balanced engagement with the spool. Detent arrangements of this type are intended to provide balanced forces acting upon the spool and thus allow freer travel of the spool in its bore.
However, even with such balanced arrangements, various factors still tend to result in side loading of the spool and thus interfere with movement of the spool in its bore. The most prevalent causes of unbalanced forces have been found to include manufacturing tolerances relating to both the valve body and spool as well as variations in the length and load rate for springs associated with different detent elements.